Various kinds of lightguide elements are known for focusing of light. The light from one or more light sources, such a light-emitting diodes (LED), halogen, xenon or discharge lamps is put into the lightguide element in the light input area and then gets to the light output area in various ways. The light emerging there then creates a light function, such as a position light, a daytime running light (DRL), or a blinking light.
AT 009 091 U1 shows a lightguide element with a light input area and a light output area, wherein lightguide rods are provided between the areas that expand in fanlike manner and have different cross sections. The light rods here are configured as recesses in the lightguide element.
EP 1895228 A1 shows a device with three zones, wherein the first zone serves for putting in the light, the second zone uniformly distributes the light and in the third zone the light emerges once more. Corresponding optical elements in the second zone provide for a uniform luminance.
WO 2011/021135 A1 shows a lens arrangement for a lighting source, opening out like a pot and consisting of striplike lightguide elements. The light of one lighting source—such as an LED—is distributed via the lightguide elements in the direction of a platelike light exit surface.
DE 698 33 421 T2 describes a light output optics for automotive signal lamps that comprises a plate of material nontransparent to light, in which openings with concave and convex surfaces are made, functioning as cylindrical lenses and enabling a uniform light distribution across the nontransparent plate.
The drawback to these known solutions, in particular, is that the light exiting via the light output optics is usually distributed inhomogeneously for structural reasons, which is especially the case when using light sources with very pronounced main beam direction, such as LEDs, and this is undesirable. As a result, the light exiting through the light output area has nonuniform brightness or the light source is shown prominently.
Often the known lightguide elements can be made only with difficulty by economical injection molding methods, since the small-sized recesses and openings in the mold separation area can cause burr, resulting in substantial light losses. Accordingly, the tools and dies are relatively expensive in the manufacture and operation (maintenance expenses).
It is therefore one problem of the invention to provide a lightguide element that produces a uniform light distribution regardless of the light source used.